Difference between setevent and CCriticalSection Lock and Unlock?

Question

0.00/5 (No votes)

See more:

What is the difference between SetEvent() and CCriticalSection class Lock() function. i cannot understand it. because it has same functionality confused me. any idea?

Posted 19-Oct-12 21:24pm

Sajeesh Payolam

Add a Solution

2 solutions

Solution 1

The SetEvent()[^] call, releases threads that are waiting for the event to be signalled. The CCriticalSection::Lock()[^] function waits for an object to be signalled. Thus they are not the same.

Posted 19-Oct-12 23:10pm

Richard MacCutchan

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

Santhosh G_ · Accepted Answer · 2012-10-19T23:16:00

SetEvent() and Lock() are not similar. SetEvent() signals the Event object, and any waiting threads will notified it.
CriticalSection is normally used to access a shared resource[like heap memory accessed by two threads] within a process.

CriticalSection::Lock() gains access to a shared resource, if any other thread accesses the same resource[that thread already called CriticalSection::Lock() of the same CriticalSection], then CriticalSection::Lock() will blocked until other thread UnLock() the critical section.

I hope your question is the difference between Event and CriticalSection.

You can achieve functionality of a CriticalSection with an Event. But the reverse is not possible.

Event and CriticalSection is used for synchronization.
A CriticalSection is limited in the process, But event can be accessed from other process.
Therefore we can achieve synchronization of two threads in different processes with an Event. But CriticalSection can only synchronize threads within the process.

Event is a kernel mode object, and CriticalSection is user mode object. Therefore the processing time of CriticalSection functions are[EnterCriticalSection, LeaveCriticalSection] is less comparing to Event functions[WaitForSingleObject and WaitForMultipleObjects].